Leakage of chemical and light-cured basing materials

This study investigated the sealing properties of chemical and light-cured basing materials in dentin. Fifty extracted molars were selected and cleaned. Slot preparations with standard dimensions were made. The prepared cavities were filled with Cavitec, Life, Ketac-Bond, VLC Dycal, and Cavalite materials. Samples were immersed in 0.05% crystal violet solution for 2 hours. The samples were then embedded in clear casting resin, sectioned, and examined with a microscope. Results indicated that Cavalite and Ketac-Bond materials allow a greater degree of dye penetration that the three other materials. Cavitec, VLC Dycal, and Life materials were similar to each other in degree of dye penetration.

Spontaneous resolution of pulmonary stenosis

Pulmonary stenosis diagnosed in infancy usually increases in severity with age or, if it is mild, may remain so for many years. We report the case of a child in whom moderately severe pulmonary stenosis in infancy appeared to completely resolve by the age of 8 years.

Psychosocial factors influencing outcome in patients with low-back pain

A psychosocial analysis of 58 patients with low-back pain was conducted. Three groups of patients with different outcomes were delineated with distinctly different psychosocial profiles. Patients who recovered uneventfully had a better income, reported more satisfaction with hospitalization or medical personnel, and had prolonged pain-free periods. Patients with the worst outcomes in terms of poor work role adjustment and severe pain complaints were more likely to be immigrants from mainland China, to be engaged in heavy manual labor, to be involved in compensation claims for work-related injuries, manifested a high degree of anxiety and depressive symptoms, and were hostile toward medical personnel. An intermediate group of patients with adequate work role adjustment but severe to moderate levels of pain were characterized by being females with varying combinations of anxiety and depressive symptoms. A preliminary clinical interview guide for screening potential problematic patients was developed.

A prospective study on 284 digital fractures of the hand

We report a prospective study on 284 digital fractures of the hand in 235 patients. Management followed clear guidelines set out in a protocol. Important factors in the selection of the treatment method were, acceptable alignment, functional stability, and associated "significant" soft tissue injuries. "Functionally" stable fractures treated by free mobilization had satisfactory results. Unstable fractures treated by splints or Kirschner wire fixation produced unsatisfactory results. "Open fracture," "comminuted fracture," and "associated significant soft tissue injuries" were identified as unfavorable prognostic factors. The anatomic site of the fractures was not important in determining the final outcome. About 15% of the displaced fractures became functionally stable after closed reduction and their results were comparable with the undisplaced fractures. About 30% of the patients had various degrees of difficulty after they returned to work. About 14% of the patients eventually changed their jobs because of their residual disability.

Propranolol induced bradycardia in tetralogy of Fallot

When an 18 month old girl who had tetralogy of Fallot and episodes of severe cyanosis with loss of consciousness was treated with propranolol there was some improvement. But when the dose was increased she had further episodes of near syncope. Holter monitoring showed extreme intermittent bradycardia with pauses of up to 2.6 seconds. The episodes of near syncope and the bradycardia resolved after propranolol was stopped. Apparent failure of propranolol treatment may on rare occasions be related to drug induced bradycardia rather than to continued episodes of severe cyanosis.

Curing light-activated composite cement through porcelain

The purpose of the study was to determine the exposure times needed to harden a light-activated composite cement through various thicknesses of porcelain. A negative exponential model was developed with which the relative hardness of a composite could be predicted from the product of the exposure time and the square root of the light intensity at 470 nm. Hardness data obtained by varying the exposure time and porcelain thickness were found to fit this model. A relationship was derived to predict the required exposure time, t, of a composite under porcelain with a transmission coefficient, Tc, and a thickness, l:t = toTc-1/2, where to is the exposure time of the composite alone.

Myelin basic protein binds GTP at a single site in the N-terminus

Myelin basic protein from normal human brain was ADP-ribosylated with Cholera toxin, but not with Pertussis toxin. It bound azido-GTP at a single site in the N-terminal tetrapeptide at the Gln residue. The binding was considerably reduced when GppNHp was present during azido-GTP binding and totally inhibited when GTP gamma S was present. The relevance of this specific binding is not understood at this time.

Tumour infiltrating lymphocytes in nasopharyngeal carcinoma

Tumour infiltrating lymphocytes were studied in 28 cases of undifferentiated carcinoma using a panel of monoclonal antibodies. For the T subsets we used OKT4 (helper/inducer), 8 (suppressor/cytotoxic), 11 (pan T), 9 (transferrin receptor) and Dako T6. For the B cells we used polyclonals IgM, D, G and A. Others were HNK-1 (natural-killer cells), THB-5 and W6/32 (HLA-ABC) and HLA-DR. Most of the lymphocytes were T cells and in 26 of 28 biopsies there were more T8 than T4 cells which could be seen around and within the tumour masses. There was also an increase in HNK and T6 cells. Tumour cells were positive for both W6/32 and HLA-DR. Occasional THB-5 positive cell could be seen within tumour masses. All tumour cells stained strongly with keratin and cytokeratin.

Effusions in the knee in elderly patients who were operated on for fracture of the hip

The incidence of an effusion in the knee in 155 consecutive elderly patients who had been operated on for a proximal femoral fracture was studied. The preoperative incidence had been 7.7 per cent in the ipsilateral knee and 1.3 per cent in the contralateral knee. Postoperatively, fifty patients (32.3 per cent) had an effusion on the ipsilateral side. In seven of them, the effusion had been present before the operation. All of the effusions subsided completely within three weeks after the operation. Results of the laboratory analysis of a specimen of the effused material from eight patients who were chosen at random showed non-inflammatory fluid. Probably the effusions were traumatic in origin, and it is likely that they were a response to stresses that had been incurred during the operation or at the time of fracture.

Treatment of unstable intertrochanteric fractures with Sarmiento valgus osteotomy and acrylic cement augmentation

Seventy unstable intertrochanteric fractures (Kyle III) were treated by Sarmiento valgus osteotomy, fixation with a sliding hip-screw and plate, and augmentation of the posteromedial upper femoral defect with acrylic cement. Immediate full weight bearing walking was started after the operation. Forty-two patients were followed up for more than 1 year (average 21.4 months). Excellent or good results were obtained in 71.4 per cent. However, there was mechanical failure in which the hip screw cut out of the femoral head superolaterally in 8.6 per cent. Comparison was made between the results of the present technique and our previously reported technique which consisted of Dimon-Hughston medial displacement osteotomy, fixation with sliding hip screw and acrylic cement augmentation to the upper posteromedial femoral defect. It was found that the result of the latter technique is slightly better, probably because of the more rigid reduction.